Extreme heat often results in the highest number of annual deaths among all weather-related hazards. In most of the United States, extreme heat is defined as a long period (two to three days) of high heat and humidity with temperatures above 90 degrees. In extreme heat, evaporation is slowed and the body must work extra hard to maintain a normal temperature. This can lead to death by overworking the human body.

Remember that:

• Extreme heat can occur quickly and without warning.
• Older adults, children, and sick or overweight individuals are at greater risk from extreme heat.
• Humidity increases the feeling of heat as measured by a heat index.